Federal agencies were ordered to beginning shutting down late Monday evening amid finger-pointing between Democrats and Republicans as to who was responsible for the United States’ first government stoppage in 17 years.

“Unfortunately, we do not have a clear indication that Congress will act in time for the President to sign a Continuing Resolution before the end of the day tomorrow, October 1, 2013,” said Sylvia M. Burwell, Director of the White House Office of Management and Budget in a memo. “Therefore, agencies should now execute plans for an orderly shutdown due to the absence of appropriations.”

Earlier Monday evening, the Senate killed the House of Representative’s continuing resolution that would have funded the government while delaying the Affordable Care Act by one year. That sent the debate back to the House, where Republican leaders moved to appoint negotiators to a joint House-Senate conference in order to work out the differences between the two chambers’ government-funding bills.

House Majority Leader Eric Cantor (R-Va.) tweeted that the House would have one final vote Monday evening pushing its latest Obamacare-delaying amendment while also requesting a conference with the Senate.

Members are advised: the House will vote tonight to adopt a motion insisting on our last amendment and request a conference with the Senate.

Throughout the night, Democrats and Republicans engaged in a battle of blame over the shutdown. “Republicans are still playing games,” said Senator Majority Leader Harry Reid (D-Nev.) of the House Republicans’ conference plans. “We will not go to conference until we get a clean [continuing resolution].”

Speaker of the House John Boehner (R-Ohio), speaking before an earlier vote on the House floor, said that “all the Senate has to do is say yes and the government’s funded tomorrow.”

“They have lost their minds,” Reid responded after that vote. The Senate later stripped Obamacare-delaying language from the House bill and sent back to the House a “clean” continuing resolution.

From the White House briefing room early Monday evening, President Barack Obama said military paychecks and Social Security benefits would continue, but that many other government functions critical to economic growth would not. He said his signature health care reform law, which Republicans have been attempting to block as part of the shutdown standoff, would be implemented regardless. And he warned a shutdown would throw a “wrench” into the country’s fragile economic recovery.

“Of all the responsibilities the Constitution endows to Congress, two should be relatively simple: pass a budget and pay its bills,” Obama said. “A shutdown will have a very real economic impact, right away. The idea of putting Americans’ hard-earned progress at risk doesn’t make any sense.”

Obama called four top Congressional leaders, including Speaker of the House John Boehner (R-Ohio), Monday evening to discuss the shutdown. Per the White House, Obama “made clear to the Republican Leadership that they must act, as the Senate has, to pass the bill that funds the government for six weeks that doesn’t include any extraneous ideological riders.”

Boehner spokesman Brendan Buck said “the speaker told the president that Obamacare is costing jobs and that American families are being denied basic fairness when big businesses are getting exemptions that they are not. The call lasted nearly ten minutes.”

House Republicans, for their part, aimed to take one more swipe at using the threat of a shutdown to scale back Obama’s signature healthcare reform law, voting earlier Monday evening on a continuing resolution that would fund the government but also delay the mandate that individuals buy health insurance, which is at the heart of the law.

“None of us want to shut down the federal government. No one’s advocating for that,” Utah Republican Rep. Chris Stewart said. “Many of us feel like this [health care] law is going to hurt millions of Americans and they’re going to avoid that if they can.”

However, Senate Democrats and the White House continued to insist that only a clean funding bill would pass muster.

At a news conference later on Monday, Boehner toward reporters bluntly: “That’s not going to happen.”

And after the Senate easily stripped out language from an earlier House-passed bill that would have delayed implementation of the entire health care law for a year, Republicans in the House blamed Democrats controlling the upper chamber for bringing the country closer to the brink.

“We think we’re in negotiation with the Senate. They’re the ones trying to run out the clock,” Oklahoma Republican Rep. Tom Cole. “As soon as we get their proposal we’re going to react right away, put it right back in their laps. … If they do something we’ll kick it back again.”

Late Monday night, Obama signed a bill to ensure military personnel are still paid during a shutdown; the House-passed bill was passed in turn on a unanimous voice vote by the Senate on Monday.

But Obama reiterated Monday evening that he wouldn’t negotiate over the health care law, hours after his top spokesman said Republican demands for him to do so or risk a government shutdown amounted to “extortion.” The President said he was willing to negotiate over long-term budget issues, but taking aim at tea party Republicans, he said, “one faction of one party in one house of Congress in one branch of government doesn’t get to shut down the entire government just to re-fight the results of an election. Keeping the people’s government open is not a concession to meet.

“You don’t get to extract a ransom for doing your job, or doing what you should be doing anyway, or just because there is a law you don’t like,” Obama said. “The American people sent us here to govern.”

As the blame game between Obama and House Republicans came to resemble a ping-pong match, some senior Senate Republicans lamented that their party seemed to be playing a losing hand.

“We may do this for a day. We may do this for a week. We may do this for a month. It’s going to end up the same way,” Arizona Sen. John McCain said. “It ends by us not repealing Obamacare.”

The latest House bill, which the Senate rejected Monday just hours before a government shutdown took effect, marks Republicans’ third attempt to pare back Obamacare as a condition of keeping the government open, after voting to defund the entire law 10 days ago and voting Saturday to delay it for a year.